This invention relates to an electronic musical instrument of a numerical value processing type incorporated with a vibrato effect.
A vibrato effect is a performance effect produced by slightly increasing or decreasing the pitch of a musical tone having produced about seven times per second thereby obtaining sweet and confortable musical tones. The vibrato effects can be classified into a normal vibrato effect and a delay vibrato effect. The normal vibrato effect provides a vibrato effect of a definite magnitude concurrently with the commencement of the musical tone whereas according to the delay vibrato effect, the vibrato effect is increased to a maximum extent as the time elapses from the commencement to the musical tone. In the performance of such musical instruments as violines and flutes, this delay vibrato effect is used advantageously.
Since the normal vibrato effect and the delay vibrato effect enrich the musical tone use of them is highly desirable also in electronic musical instruments. For this reason, electronic musical instruments have been proposed capable of manifesting the normal and delay vibrato effects.
In the prior art electronic musical instrument, for the purpose of manifesting both of the normal and delay vibrato effects independent vibrato control circuits are provided so that not only the construction of the circuit is complicated and expensive, but also their operations are troublesome.